Victorian Chimney flashing

[housewinnie]

Hi all and thank you in advance for any tips.

Need to redo the flashing around the chimney on our house. The roof is the original clay double Roman tiled with lath and plaster underneath. I am planning to just replace the lime mortar flashing which has failed with a 2 to 1 mix as I can do this myself. bad idea or should I get someone in to redo withy lead?

Cheers

 

[Cubist]

Frankly, it's not a good idea. You will need to use lead, or some other impermeable material, to prevent water penetration around the chimney and into the wall spaces below which could prove very damaging to the house.

 

[paulc]

Had a fillet of mortar down the side of my chimney. Had been OK when the house was built.... Then it started leaking and some rot set in to one of the timbers. Would have been OK if there had been a hidden soaker chased in. Have now replaced the mortar fillet with a strip of lead.

 

[Feltwell]

Lead every time. The whole design is so that you can have some differential movement between the tiles, which are sat on timbers that will always move a little bit with humidity changes, and the masonry stack, which does not but which may move in the wind a little.

Bridge that gap with any sort of mortar and eventually it will fail. Do it with lead and properly installed it will outlive you and never leak.

Where the lead is chased into the brickwork, I would seal it in with CT1 sealant (they do a silver version, plus you'll need their multi-solve to finish it) rather than mortar. CT1 should last longer than lead sealant.

 

[housewinnie]

Cheers for the replies, so lead it is then, does it need soakers if there are none already in place. as not sure I want to start disturbing the tiles too much as it's the original 140 year old roof of which most is in pretty good shape

 

[housewinnie]

So, have done some searching around and it seems that as I have profiled double Roman tiles as long as the flashing goes over the profile no soakers are required? cheers again

 

[Lacan07]

Cheers for the replies, so lead it is then, does it need soakers if there are none already in place. as not sure I want to start disturbing the tiles too much as it's the original 140 year old roof of which most is in pretty good shape

Lead soakers only really really required if you suffer unusual winds / driving rain, or of the chimney is at an angle / slope to the tiles. If you can lift one of the tiles near the chimney see if its wet underneath.

 

[malcolm]

With the Roman tiles so long as the flashing goes over the ridge the water will be well away from the chimney and can't get back.

 

[stuart45]

Soakers don't work with single lap tiles because they aren't supported from below as they would be with double lap. Secret gutters are a modern method of belt and braces single lap.

 

[housewinnie]

 

[housewinnie]

A couple of pics, one of flashing and one of pointing. Have pointed up that area and will post a pic later of my efforts.

Have deceided to do it in small parts as some of it is non existant and do not want to get involved in loose bricks and an unstable chimney.

 

[housewinnie]

 

[housewinnie]

Not my best work but my first time using premixed putty lime mortar. Got a little more on bricks than wanted was being careful but hey its alot more solid than it was and from the ground you cannot tell the difference. Little bit at a time..

 

[housewinnie]

Well this is the other chimney.what was to be a pointing job has turned into top 3 courses needing a rebuild. Wish me luck as this is also a first for me.

 

[stuart45]

Your pointing looks fine. When you build an oversailing course, there is a tendency for the brickwork to sink down a bit at the front, so make the bed joints a bit thicker at the edge, and taper them in. This will allow for the bricks to settle in the correct position.
Normally with brickwork you put the level on top of the bricks, but with an oversailing course it's often the bottom edge that catches the eye, so in this case it's better to level the bottom edge. You can see in the photo of the pointing how the bottom edge of the oversailing course shows up.

 

[housewinnie]

cheers for the tip Stuart

 

[housewinnie]

Having never done any bricklaying fingers crossed I may have pulled it off.

 

[housewinnie]

Next up remove aerial and start raking out the rest.

 

[a twig]

That’s a great bit of work - what a bricklaying baptism of fire! definitely wouldn’t have said that’s your first time - well done!

 

[stuart45]

Really good. Well done.